As stated in my aforementioned application Ser. No. 07/333,136, there is a need for a compact hydraulic drive unit composed of three or more reversible drive sections which have the capability of being moved either in unison or separately. One use for such a compact drive unit is for powering the floor members of a reciprocating floor conveyor.
Basically considered, a reciprocating floor conveyor comprises at least one group of at least three elongated floor members and a hydraulic drive system which operates to drive at least a majority of the floor members in unison in the desired conveying direction, and to retract them individually. Systems are in use in which all of the floor members are driven in unison, in the desired conveying direction, and are then individually retracted sequentially. It has also been proposed to drive a majority of the floor members in the desired conveying direction while at the same time retracting the remaining floor slat members. The present invention has application to both types of systems.
For background purposes, reference is made to my aforementioned U.S. Pat. No. 4,817,783, to my U.S. Pat. No. 4,793,469, granted Dec. 27, 1988, and entitled Reduced Size Drive/Frame Assembly For A Reciprocating Floor Conveyor, to my U.S. Pat. No. 4,821,868, granted Apr. 18, 1989, and entitled Drive/Frame Assembly for a Reciprocating Floor, and all of the prior art that is disclosed in such patents.
A principal object of the present invention is to provide a hydraulic drive unit of the general type disclosed by my aforementioned Pat. No. 4,817,783 which is of a simplified construction and is capable of being controlled by valves which are separate from the piston rod and the cylinder bodies. A second object of the invention is to provide an improved and simplified control system for the hydraulic drive unit of the invention.
The contents of my aforementioned U.S. Pat. No. 4,817,783 and my copending application Ser. No. 07/333,136 are both hereby fully incorporated by reference into the subject disclosure.